Soo Locks close for the season

The Burns Harbor locks through as the last vessel in the Soo Locks for the 2019-20 season. The locks closed this morning.

The Soo Locks wrapped up its active maritime season just before 7 a.m. ET after the Burns Harbor locked up into Lake Superior at Sault Ste. Marie, Michigan.

“The M/V Burns Harbor was the final cargo vessel of the 2019 Navigation Season through the Soo Locks,” the U.S. Army Corps of Engineers Detroit District posted on its Facebook page along with this photo. “She passed through the Poe Lock this morning at 6:44 a.m. on her way to Superior, Wisconsin, for winter lay-up. At the Soo Locks, crews will begin the dewatering process today, kicking off a busy season of maintenance projects.”

The locks would remain available to downbound traffic out of Lake Superior until midnight today, but Kevin Spraque, chief Soo area engineer for the U.S. Army Corps of Engineers, said Tuesday that there were no vessels heading to the locks that would arrive by midnight. “The rules say stay open for a vessel that leaves Lake Superior by midnight tonight, but we’re not tracking anybody in the system that’s going to do that.”

With news of potential strong winds on Thursday, the locks crew wants to get to work putting into place the bulkheads that help with removing the water from the Pock Lock as soon as possible. The 50-ton bulkheads, about 120 feet long and 5 high, make imposing “sails” and cannot be put into placed with the crane during high winds, Kevin explains.

The winter layup season will be a busy one because the Poe, the hardest working of the two locks remaining, must undergo some major repairs and maintenance. The Poe has redundant sets of downstream gates, but the concrete sill on one set failed this summer and the lock had to be shut down twice for repairs, once for seven hours in late August and again a couple weeks later for about five hours. The intermediate gates were used, which required gate heaters to be installed, so it was good the final weeks of the season have been warm, Kevin says. Repairing those sills, along with reviewing deteriorating concrete on the single upstream set of gates, will be part of the work for winter. “That’s our most critical gate,” Kevin says of the upstream set, “because we don’t have a redundant gate.” 

Summer work on the locks means use of divers, but in winter, when the locks can essentially be put into their own “drydock,” work can be handled above the water. This winter there will also be welding, painting, girder flange repairs, addition of stiffeners and other tasks. Kevin expects the crews to be working close to the March 24-25 midnight deadline for reopening. “We like to be done a week earlier so the Coast Guard can lock up to Duluth,” he says.

The 1,200-foot-long, 110-foot-wide and 32-foot-deep Poe Lock handles about 90 percent of all cargo that passes through the locks. The smaller MacArthur Lock, considered “seaway sized” at 800 feet long, 80 feet side and 31 feet deep, can accommodate the ocean-going salties, but cannot handle the larger lakers, especially the 1,000-footers. The Davis and Sabin locks are not operational and will be replaced by a new lock of the Poe’s size. Initial funding of $191.6 million is in place to start the $922.4 million project, but Kevin points out that lock will be at least a decade in the making.

The Poe Lock gates will be a priority, Kevin says, calling their repair “a multi-year project … to buy 10 years time.”